This paper summarized the separation effects of different electrodialysis systems on lithium in Salt Lake, including single selective electrodialysis, ionic liquid membrane and bipolar membrane, among which ionic liquid membrane with a broad development prospect possesses the characteristics of high recognition of Li⁺, long?term stability under electrolysis and low energy consumption. Furthermore, the advantages, disadvantages and tendency of prospective development of different electrodialysis systems in lithium extraction from Salt Lake were analyzed, and the industrialization research on the application of electrodialysis systems for lithium extraction from Salt Lake was analyzed.

      There is usually a starting pressure gradient in the tight oil. This article considers the seepage law of the crude oil flowing from the matrix to the fractures in the formation under the premise of starting the pressure gradient and some assumptions. Through the establishment of numerical model, the relationship between the pressure, permeability, core size and other factors and the degree of failure recovery in the onedimensional space is analyzed, as well as the threedimensional plate is drawn. The results show that when the core scale is very small, the main factors affecting the degree of recovery are the failure pressure difference. At the same time when the scale increases, the relationship between the recovery degree and the core length and permeability is more and more significant. Then, based on the conclusion of the previous the paper put forward the empirical formula considering the degree of calculation and recovery under various factors, and extend the space to three dimensions. On the basis of one dimensional revise the formula, the empirical formula of the failure rate of three dimensional matrix failure is obtained. It provides some reference for production practice.